Oil and grease interceptor



Dec. 23, 1947. Y E. w. N. BoosEY 2,433,087

' r OIL AAND GREASE `INTEfmEPTOR Filed Dec. l, 19425 47 Y 3/ a/a 46 47 4 "5 47 l Y E in 3M 49 l I 49 l 48 48 42 l l 30 l 1 v 44 l UPI -f l ATTORNEY Patented Dec. 23, 1947 UNITED STATES PATENT OFFICE OIL AND GREASE INTERCEPTOR Edward W. N. Boosey, Detroit, Mich. Application December 1, 1943,'Serial No. 512,676

(c1. isz-9) 6 Claims.

This invention relates to oil and grease interceptors such as are used, for example, in restaurant kitchens to prevent the ow to the sewer of oils and greases discharged with water from sinks and dish washing machines.

One object of the invention is the provision of an interceptor which embodies an improved y vent for the air and gas space at the top of the interceptors liquid receiving chamber, and which interceptor is so constructed as to enable the liquid in said chamber to be normally maintained at a high level, even though the interceptors water outlet orifice is located at a low level.

A further object of the invention is the provision of an interceptor having an effective air lock between the air and gas space and the water outlet orice, said air lock maintaining in said space a substantially constant volume of air and gas at a substantially constant head or pressure and preventing or minimizing surging effect of the incoming liquid, such as would otherwise normally occur on sudden inflow.

Still another object of the invention is the provision of an interceptor having structural simplicity, a relatively high capacity and improved operating eiciency.

Further objects of the invention are in part obvious and in part will appear more in detail hereinafter.

The invention will be readily understood, and many of its practical advantages will be referred to in, or will be evident from, the following description of the preferred structural form of such invention, as illustrated in the accompanying drawings, in which Fig, 1 is a longitudinal sectional View of the preferred form of interceptor embodying the present invention, the view being on the line l-l of Fig. 2;

Fig. 2 is a transverse sectional view, on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary longitudinal sectional view, on the line 3-3 of Fig. 4, of still another form of interceptor embodying the present invention; and

Fig. 4 is a transverse sectional view on the line li-d of Fig. 3.

Before the interceptors here illustrated are specically described, it is to be understood that the invention here involved is not limited to the details of construction or the arrangement of parts here shown, as the invention obviously may take other forms. It also is to be understood that the phraseology or terminology herein employed is for purposes of description and not of limitation, the scope of the present invention being denoted by the appended claims. i

In all of the forms thereof here shown, the interceptor embodies a-closed tank or vessel of relatively large capacity and to which is admitted, throughan inlet orifice in one of its side walls, the oil and/or grease-containing liquid discharged, for example, from a sink or a dish washing machine. Through said inlet orifice, the discharged liquid, and more 'or less air, flows to the main chamber of the interceptor, preferably by way of some means which retards liquid flow and assists in the stratification of the oil, grease and water, the oil and grease collecting on the top of the water for retention in said chamber. From this main chamber, and preferably from a low level therein, the water flows upwardly through the generally upright channel of an outlet conduit, from which it flows over the upper edge of a wall serving as a dam or Weir into'a discharge or spill-over chamber. Communicating with this chamber is the water outlet orifice of theintereeptor, said orifice being located, at least in part, below the top edge of said dam or Weir-forming wall and communicating with the sewer to which the water, now freed of its oil and grease, is to be delivered. The top edge of this wall (or the crest of the dam or Weir, to put it another way) determines the normal liquid level in the main chamber and in the water outlet channel leading therefrom, so that theV interceptors water outlet orificeV may be located at as low a level as desired. For the purpose of stabilizing operating conditions, the air and gas space at the top of the main chamber is vented to the generally upright water outlet channel, the vent preferably (but not necessarily) embodying or being associated with an air lock or liquid seal which normally prevents direct communication between said air and gas space and the spill-over chamber and hence between said air and gas space and the water outlet orifice. In any event, the parts establishing the air vent and the dam or Weir-forming wall are so constructed and arranged as to prevent or minimize surging effect of the incoming liquid, such as would normally occur upon a sudden gush or inflow of liquid and air into the interceptor.

Referring now to the interceptor of Figs. 1 and 2, shown as made of metal but which may be made of any suitable material, it will be noted that such interceptor comprises a body 3|) having a removable cover 3l, the body and cover together enclosing the main chamber. 32. To re-` ceive the liquid discharged by a sinkv or a dish washing machine through the pipe 33, one of the side walls of the body 30 is provided with an inlet orice 34, and through such orice, the incoming liquid enters the generally upright channel 31 of a conduit; 35, open at its bottom and at its top to the main chamber 32. The provision of this conduit, with its open ended channel 3l, retards the velocity of the incoming liquid and initiates stratification of the oil, grease and Water. To assist in :effecting 'such fstratication, the wall portion 36 of the conduit, opposite the inlet orifice 34, may be inwardly and upwardly inclined, as here shown.

The wall portion 36 due to its inclined relationship tends to retard the velocity of. flow of liquid thereinto whereby time is afforded for the water to iiow downwardly in the channel 37 of the conduit 35, to thereby enter the chamber 32 adjacent the bottom thereof. Similarly, the grease `and oil, together with the incoming air, are caused to iliow, 'to .a greater or lesser extent, upwardly in the channel 3J and thus enter the upper .portion of the chamber 32.

.Adjacent a side wall of thebody 3U', there is a water 'outlet vconduit 39 'having an Iopen lower end Vadjacent but spaced from 'the bottom wall of said body. After being vfreed of its grease and oil, the water `enters the open lower end of 'this conduit and nows upwardly through "the channel 38 'provided thereby. To 'one side vof the upper endfportion of said Vwa-te'r'out'let conduit, :there is aspilleover chamber 142, :and the top edge '44 of a wa'll portion 143 between the lchannel of `such conduit and `said chamber `servies as the ldam lor we'i-r Afor determining the ynormal liquidlevel .'(indi'cated by the ydot-dash line 11a- A in Fig. 2) in the main 'chamber 32 and .in the channel 3B -of the water outlet .conduit 139. 'Communicating with the spill-over chamber 42 and located ventirely below the normal liquid level A-.A 4is the 'water outlet oricell lwhicl'i communicates by a pipe V1H or the like'with the-sewer to .which the vwateris fto be discharged. The vlocation of th'e 'bottom wall 40 of the spill-over chamber determines the depth of-such chamber and .hence the levelto which 'the water outlet :orifice 45 canbe lowered. It is quite evident, however, 'thatsuch outlet ori- 'ce can be located at a lmuch lower level than that here shown @if the spill-over chamber is given the necessary depth.

In this form of -the'inventi'on, the top of the spill-over chamber `42 and the entire upper end ofthe lwater outlet channel 313 are covered 'by .a closure member 46, releas'ably held lin lsealng position, in spaced relation to the top Aedge 44 ofthe dam lor vvveir-forming wall portion 43, by the idepending `feet 34u of "the 'body r"cover Therefore, by simple lremoval fof the bolts 41 which neleasably `hold 'the body cover infs'ealing position, :the closure member 4B may be readily lifted from Aiits seat upon the upper edges Vof the external iside walls which form the spill-over chamber 42 and the upper end portion of the water outlet conduit 39.

'For venting itheair and gas space at tlietop of 'the main chamber 432, the closure member 46 has extended therethrough a tube 48, Vhere shown as integral with said'closure member. The open-upper endof said tube is in communication with said'air -and gas space, and the-open lower end -of said tube is in communication with the water channel '38 ofthe 'outlet 4conduit '39.. Inasniu-ch-as the vlower end of lsaid tube is below the normal liquid V-level A-A, indicated in Fig. 2,

the vent passageway provided by vsaid tube is normally sealed by the water in said channel.

If desired, and as here shown, the cover 3I` of the interceptor of Figs. 1 and 2 may have a domeshaped portion 3|b which overlies the open upper end of the vent-forming tube 48, and for manufacturing simplicity and economy, the spillover chamber 42 and the water outlet conduit 39 may be integral parts of a unitary structure detachably mounted within the main chamber 32 on the inwardly projecting end of the water discharge pipe 4| leading to the sewer. The operation of the interceptor of Figs. 1 and 2 will be evident from the foregoing description of its construction.

In Figs. 3 and 4, there is fragmentarily shown an interceptor which differs but slightly from the Vone shown in Figs. 1 and 2, and corresponding parts of these two interceptors are therefore designated by the same reference numerals. Primarily, the interceptor of Figs, 3 and 4 differs from the interceptor of Figs. 1 and 2 in that its spill-over chamber 42 is located above a part of the lower end portion of vthe upright channel 38 of the water outlet conduit 39, and in that the lower end of the vent tube 48 terminates above the normal liquid level, as determined by the top edge 44 of the wall i3 which separates the spill-over chamber d'2 `from the upper end portion of the water outlet channel 38. Notwithstanding the fact vthat the lower end of the vent tube 48 is above the normal liquid level, there is a control of liquid surge in this interceptor. This control occurs because of the rise of liquid level upon initial iniiow of liquid to the interceptor, effecting a temporary submergence of the lower .end of the vent tube 43 and thereby providing a temporary liquid seal which enables the air and gas in the space above the main chamber to dampen any tendency for excess surge. In 'this form of the invention, the closure member '46 for the spill-over chamber 42 and the water outlet channel 38 is bolted in place, as at 49, although if desired such closure member may be held in place by depending feet of the body cover 3|, as in that form of the invention shown in Figs. 1 and 2.

It will be evident from the foregoing description and drawing that the various features and objects of the invention are attained by the structural arrangement and vform of the several parts hereinbefore described. Having thus briey described my invention, its utility and mode of operation, what I claim and desire to secure by Letters Patent of the United States is:

1. A grease interceptor, comprising a body having a removable cover providing an air-tight chamber and an inlet thereto, a conduit open to the lower portion of said body chamber and providing an upwardly extending liquid outlet channel, a closure for the upper end of said conduit and the channel thereof, a series of lugs on the cover engaging the closure to maintain the same in position, Wall means providing a discharge chamber within the closed upper end portion of said outlet conduit, there being a discharge passageway from said outlet channel to said discharge chamber, said body being provided with a discharge orifice in communication with said discharge chamber, the bottom of said discharge oriiice being located at a lower level than that of the bottom of said passageway at said outlet channel, the bottom of said passageway at said outlet channel thereby determining the normal liquid level in said body chamber and in Asaid channel, and a vent conduit for an air and gas space at the top of said body chamber, said vent conduit extending through said closure with its upper end in communication with said air and gas space, the lower end of said conduit extending down into said outlet channel and terminating below said discharge passageway, whereby said vent conduit is normally sealed from said discharge chamber by the liquid in said vent channel.

2. A grease interceptor, comprising a body providing an air-tight chamber, an inlet thereto, a conduit open to the lower portion oi said body chamber and providing an upwardly extending liquid outlet channel therefrom, means including a cover providing an air-tight discharge chamber laterally of said outlet channel, there being a common wall portion between said discharge chamber and said outlet channel which terminates below the top of said chamber and above the top of said outlet channel, with the consequent establishment of communication between said chamber and said outlet channel over the upper edge of said wall portion, said body having an outlet orice for said discharge chamber which communicates with said chamber below the upper edge of said wall portion, whereby said upper edge of said wall portion determines the normal liquid level in said body chamber and said outlet channel, said body chamber being provided with an air and gas space above the liquid therein, and means for venting said air and gas space to said discharge chamber, said Vent means being closed by the liquid in said outlet channel when such liquid is at its normal level, said discharge chamber including a cover held in position by a series of lugs on the body cover.

3. A grease interceptor, comprising a body having a cover providing an airtight chamber and an inlet thereto, a conduit open to the lower portion of said body chamber and providing an upwardly extending liquid outlet channel therefrom, said conduit being open at its upper end, means providing a discharge chamber laterally of said outlet channel and open at its top, an air-tight closure for the top of said discharge chamber, a plurality of lugs on the cover engaging the closure to maintain the same in position said closure having a portion projecting over a portion of the open upper end of said outlet conduit, said body being provided with a discharge orifice in communication with said discharge chamber below the closure for said chamber, means 'providing a discharge passageway from said outlet channel to said discharge chamber, said passageway being located below said closure, the lowermost portion of said passageway at said outlet channel being located above the lowermost portion of said discharge orifice, whereby said passageway determines the normal liquid level in said body chamber and in said outlet channel, the uncovered upper end portion of said outlet conduit providing a vent for an air and gas space at the top of said body chamber, and means extending from the projecting portion of said closure downwardly into said outlet channel below the normal liquid level therein to thereby enable the liquid in said outlet channel to normally prevent communication between said vent and said passageway to the discharge chamber.

A. A grease interceptor, comprising a covered body having an air-tight chamberV and an inlet thereto, a conduit open to the lower portion of said body chamber and providing an upwardly extending liquid outlet channel therefrom, means providing a discharge chamber laterally of said outlet channel, an airtight closure for said discharge chamber, means carried by the cover of said body and engaging said closure for releasably holding said closure in place, there being a discharge passageway from said channel to said discharge chamber below said closure, said body having an outlet orice for said discharge chamber, and means for venting said discharge chamber and air and gas space at the top of said body chamber, to the outlet conduit.

5. A grease interceptor, comprising a covered body providing an air-tight chamber and an inlet thereto, a conduit open to the lower portion of said body chamber and providing an upwardly extending liquid outlet channel therefor, means providing a discharge chamber laterally of said outlet channel, an air-tight closure for said discharge chamber, depending projections carried by the cover of said body and engaging said closure for releasably holding said closure in place, there being a discharge passageway from said channel to said discharge chamber below said closure, said body having an outlet orice for said discharge chamber, and means for venting said discharge chamber and air and gas space at the top of said body chamber to the outlet channel.

6. A grease interceptor, comprising a chambered body having an inlet connection and an outlet connection, means within the body connected adjacent its upper end with the outlet connection and providing an outlet channel open at its lower end to the lower portion of the body chamber and providing also a discharge chamber laterally oi said outlet conduit, a wall of the said discharge chamber lying between the outlet channel,and the outlet connection and having its upper edge below the top of the discharge chamber and above the outlet connection, and a tube providing a channel opening at one end to an air space in the body chamber and at its opposite end terminating in the outlet channel at such a level with respect to the upper edge of said wall as will reduce surge in the body chamber.

EDWARD W. N. BOOSEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED sTATEs PATENTS 

